Presently, the frame surrounding the LCD is directly made of injection molded resin. Although the material cost is low, the recycle of resin material causes release of toxic substances. If direct landfill is used instead of recycle, it fails to provide effective degradation. The resin material does not meet current environmental requirements and may create many environmental problems in the future. Many countries have put strict regulations on the use of plastics. The resin material for the frame for LCD is an urgent problem for the industry to solve now.
To achieve electromagnetic interference (EMI) requirement for resin frame, a metal plate is put inside the frame to prevent electromagnetic wave and reduce radiation. Such metal plate usually is made of iron and heavy. With the resin frame, the total weight will be very heavy. The entire industry is eager to Minimize the overall weight and meet the environmental requirement. This goal is to make computer peripherals lightweight and environment-friendly, and competitive in the market.
Therefore, the industry adopted aluminum as LCD frame material. Usually casting or extrusion is adopted for aluminum processing. With consideration of manufacturing cost, the die and mold for forging process is expensive and unable to form vertically sticking rib to isolate electromagnetic wave by a one-time process. The reason is the vertically sticking rib affects the mold release. Thus, current method adopts inexpensive extrusion with low dic and mold cost. As a result, the production can provide economic benefits.
For extruded aluminum as LCD frame, electric arc welding can be only used for the middle frames, but not for the front frame. This is because black shadow or black spot is found during anode processing and it affects the aesthetic feeling for the LCD panel. So present assembly of the front frame and the middle frame made of extruded aluminum has technical bottleneck that is harmful to competitiveness and disadvantageous to sales. This is an urgent problem that the industry needs to solve now.